APKTool is an open-source command-line utility, pre-installed on Kali Linux at /usr/bin/apktool, designed for reverse engineering Android application package (APK) files. Maintained by Connor Tumbleson (iBotPeaches) and originally developed by JesusFreke, APKTool decompiles APKs into nearly original resources and smali code, enabling modifications, debugging, and recompilation. Ideal for cybersecurity professionals, ethical hackers, and Android developers, it supports vulnerability analysis, malware inspection, and app localization. With a project-like structure and automation for repetitive tasks, APKTool streamlines APK manipulation.